The present invention relates to electrostatographic reproduction machines, and more particularly to a non-leaking and easily remanufactured toner cartridge for use in such a machine.
In the well-known process of electrophotographic printing, the charge retentive surface, typically known as a photoreceptor, is electrostatically charged, and then exposed to a light pattern of an original image to selectively discharge the surface in accordance therewith. The resulting pattern of charged and discharged areas on the photoreceptor form an electrostatic charge pattern, known as a latent image, conforming to the original image. The latent image is developed by contacting it with a finely divided electrostatically attractable powder known as "toner." Toner is held on the image areas by the electrostatic charge on the photoreceptor surface. Thus, a toner image is produced in conformity with a light image of the original being reproduced.
The toner image may then be transferred to a substrate or support member (e.g., paper), and the image affixed thereto to form a permanent record of the image to be reproduced. Subsequent to development, excess toner left on the charge retentive surface is cleaned from the surface. The process is useful for light lens copying from an original or printing electronically generated or stored originals such as with a raster output scanner (ROS), where a charged surface may be imagewise discharged in a variety of ways.
In a printer, as the toner within the developer material is transferred to the photoreceptor and eventually to the copy paper, this used toner must be replaced. The printer thus includes a container or cartridge from which fresh toner is dispensed into the machine. To provide for a small, compact cartridge and to provide for a cartridge in which the cartridge may be easily removed, the cartridge typically has a compact shape.
Service costs represent a significant portion of the cost associated with operating a reproduction machine. Certain components represent those most likely to require service. By providing a method of easily replacing those certain components, the operator may replace those components himself, avoiding service technician labor costs.
These certain components are consolidated within a housing that may be easily replaced by the customer. This housing is typically called a customer replaceable unit (CRU). Typically included in a CRU are toner, a cleaning blade, the charging device (a corotron or a bias charge roll), and the photoreceptor.
A CRU is changed several times during the life of a copy machine. While a few of the components within a CRU are consumed during the life of the CRU many of the components may be reused. Therefore, the CRU is now being frequently remanufactured rather than being replaced. The remanufacturing includes refilling the CRU with new toner and inspecting all components that wear. Worn components are replaced.
The CRU must be shipped to the customer in a sealed condition. The customer must break this seal to permit toner to leave the CRU. The broken seal is removed from a used CRU housing during remanufacture. An identical seal is then placed where the original seal was located. Removing the broken seal is very difficult. The adhesive required to secure the original seal is difficult to remove from the housing. This original adhesive must be scraped from the housing, without damaging the housing so that a new housing seal will not leak.
U.S. Pat. No. 5,404,212 discloses a technique for providing an easy to remove leak-proof seal for shipment of a remanufactured toner cartridge. An adhesive-backed sealing strip is disposed over the feed roller of the hopper so that a seal is formed between the Mylar blades and the feed roller. The excess portion of the sealing strip is then passed through a foam feed roller and the lid is then sealed onto the hopper prior to shipment.
U.S. Pat. No. 4,816,877 discloses a method of refilling a toner cartridge. The cartridge has an upper portion with an upper chamber for clean toner and a lower portion with a lower chamber for used toner. The lower portion has a discharge hole opening into the lower chamber. Refilling is accomplished by piercing a hot iron rod into the plastic portion of the upper portion until a refill hole is formed. Toner is then added through this refill hole.
Toner leakage has been found to be a consistent problem with such remanufactured development apparatus cartridges. Typically, during a remanufacturing process for such cartridges, the cartridge housing is physically separated into two portions, such as so as to be able to add fresh toner and a pull strip. The two portions are later rejoined conventionally with rails or clips. During subsequent handling and use, it has been found that the fresh toner added tends to leak from the "joined" areas.